1. Field of the Invention
The present invention relates to a method and system for generating a solid model of computer graphics, and more particularly, to a method for generating progressive solid models based on a cellular topology according to a feature approach to achieve effective sharing and transmission of the model under a distributed circumstance.
2. Background of the Related Art
Generally, highly detailed geometric models are necessary to satisfy the growing expectation for realism in computer graphics.
In particular, according to conventional modeling systems, detailed models are created by applying versatile modeling operations, such as extrusion, constructive solid geometry, and freeform deformations, to a variety of geometric primitives. In order to efficiently display detailed models, they must be tessellated into meshes such as triangle meshes.
However, the resulting complex meshes are expensive to store, transmit, and render, thus motivating a number of practical solutions: mesh simplification; level-of-detail (LOD); progressive transmission; and mesh compression.
In computer graphics, models are usually represented by use of triangle meshes. However, solid models are widely used in the industry, and are applied to advanced application such as product design and virtual assembly. In addition, since these developing processes are largely proceeded under distributed circumstances, the problem of sharing and interchanging solid models over the network becomes an important issue.
In particular, in order to solve the above problem, it is necessary to generate adequate level-of-details for the solid model depending on the specific application, and to provide the effective transmitting process. The generation of level-of-details and progressive transmission of the solid model is a prerequisite to properly achieve the collaboration for developing the products under the Internet environment. However, current researches are mostly focused on triangular meshes. There are few researches for generating progressive solid models from solid models at present.
For example, several research efforts have addressed how to generate or compress progressive models from triangular meshes, such as a method of a progressive triangular mesh representation and a mesh simplification for maximally maintaining overall appearance defined by scalar attributes as well as shapes of initial mesh model, a method of quickly simplifying polygonal models by progressively applying vertex contractions using a quadric matrix, and a triangular mesh compression method, called as Edgebreaker, for coding the connectivity of arbitrary triangle meshes, which is widely used due to the efficient compressing rate. There are few researches related to the generation of progressive solid models from the solid model or compression or transmission of the solid model.